Contained bodies of water such as swimming pools, fountains, ornamental ponds and other contained bodies of water must kept free of microorganisms, and vacuumed or skimmed to keep them clean and free of larger particles and debris. Chlorine is a chemical typically used to sanitize contained bodies of water and reduce or eliminate microorganisms that can be aesthetically unpleasant, hazardous and spread disease. In addition, larger impurities and particulate matter typically must be removed from a contained body of water by skimming the surface of the contained body of water with a net, vacuuming the bottom of the body of water or by filtration.
There are several problems associated with both the use of chlorine and the use of existing methods to keep contained bodies of water free of debris and large particles.
Use of Chlorine (Cl)
Chlorine, when added to a contained body of water in sufficient amounts, kills bacteria and microorganisms by destroying lipids, enzymes and other structures within their cells. This process is known as “oxidation.”
When added to a contained body of water, chlorine breaks down into two chemical components: Hypochlorous Acid (HOCl) and one or more hypochlorite ions (OCl). Oxidation occurs more rapidly when there is more Hypochlorous present. The level of each of the Hypochlorous Acid and the Hypochlorite ions depends on a pH level of the contained body of water. As is known in the art, “pH” levels represent how acidic or basic a substance is. The pH scale ranges from 0 to 14. Pure water is “neutral” and has a pH of 7. When chemicals are mixed with pure water, the mixture either stays neutral or becomes either acidic (less than pH 7.0) or basic (greater then pH 7.0)
Hypoclorous Acid and Hypochlorite ions independently accomplish oxidation, but the Hypochlorous Acid typically oxidizes microorganisms quickly (e.g., in several seconds) while the Hypochlorite ion typically takes much longer (e.g., about 30 minutes) to accomplish the same result.
If the pH level of a contained body of water is too high (i.e., too basic), not enough Hypoclorous Acid is produced in the chemical breakdown process. Oxidation sufficient to sanitize and clean a contained body of water, for example, takes much longer at basic pH than at more neutral pH levels. Optimally, the pH levels in the contained body of water should be between around seven.
Sunlight typically speeds up the chemical break down and neutralization of chlorine. To maintain hygienic conditions in a contained body of water over time, chlorine must be continually added to the water as it breaks down.
While the bacteria-killing properties of chlorine are very useful and well established, there are many disadvantages associated with the use of chlorine. Chlorine causes itching and burning of the skin on humans. Chlorine may also exacerbate common existing skin conditions such as eczema. Chlorine frequently causes irritation to the eye and other membranes. Chlorine also has a distinctive odor that may be perceived as unpleasant. Extremely high amounts of chlorine gas in an area surrounding a contained body of water have been associated with certain types of breathing problems. The Hypochlorite ion in chlorine causes damage to fabrics, such as bathing suits.
Chlorine and its chemical components must be continuously added and pH levels of a contained body of water must be carefully monitored to maintain safe levels of both the chlorine and of microorganisms. High amounts of chlorine, due to improper monitoring of pH levels can cause chemical burns and injury to eyes, nose and throat membranes. Inadequate amounts of chlorine can result in a proliferation of bacteria and microorganisms associated with the spread of illness. The monitoring of chlorine levels is a laborious task. Costs associated with the use of chlorine in publicly and privately maintained bodies of water include not only the chemical itself, but also labor costs necessary to monitor and maintain the chlorine and pH balance in the contained body of water.
In response to the problems associated with high levels of chlorine and its monitoring, there have been many attempts to develop alternatives to reduce the amount of chlorine required in swimming pools. One attempted solution has been U.S. Pat. No. 6,551,519 that issued on Apr. 22, 2003, to Hartwig entitled “Ozone of pool water” teaches “a method for the treatment of pool water with ozone at concentrations less than previously employed. Ozonation, as described herein, provides several distinct advantages including but not limited to inactivation of Cryptosporidium and other water borne microorganisms, reduction of combined chlorine concentrations and oxidation of chloramines.”
Another attempt is covered by U.S. Pat. No. 6,139,756 that issued on Oct. 31, 2000, to Fuchs entitled “Method of treating swimming pool water” teaches “a method of treating water for a swimming pool comprising chlorination of the water, and filtration of the water using a fixed-bed filter with periodic backflushing of the filter using wash water to which a disinfectant has been added. The disinfectant is a peroxycarboxylic acid with one to six carbon atoms is used as disinfectant, preferably a solution containing peroxyacetic acid and/or peroxyformic acid and hydrogen peroxide. The method results in an improvement of the quality of the swimming-pool water and of the used wash water”
Yet another attempt to solve the problems of high chlorine levels has involved devices making use of electrical current such as U.S. Pat. No. 5,980,727 that issued on Nov. 9, 1999, to Putz entitled “Method and equipment for removing organic halogen compounds from water” teaches “a method to at least extensively remove organic halogen compounds from water or an aqueous solution, at least one magnesium or aluminum anode (1) and at least one associated electrode (2) operating as the cathode dipping into the water. The present invention also concerns equipment with which to implement the method of the invention. Both the method of the invention and the equipment of the invention are preferentially used when disinfecting water with chlorine and in particular in swimming pools.”
Use of Metals to Sanitize Contained Bodies of Water
There have also been attempts to solve the problems associated with sanitizing of pools using metals such as copper, silver, zinc and aluminum in compositions or devices to produce a biocide effect. These attempts include U.S. Pat. No. 5,149,354 that issued on Sep. 22, 1992, to Delaney entitled “Composition for treating swimming pools” teaches “a composition for treating swimming pools to inhibit the growth of algae, fungi and bacteria, and to prevent the formation of turbidity in the pool water, more particularly to reduce the dosage of chlorine or chlorine-based chemicals to maintain the pool water in a clear and pathogen-free condition, while at the same time substantially eliminating the risk of deposits and stains being formed on the pool walls, comprises by weight: from about 78 to about 83 percent of copper sulfate, from about 0.08 to about 0.12 percent of silver nitrate, from about 1.0 to about 1.4 percent each of sodium gluconate and zinc chloride or zinc sulfate, from about 16.4 to about 9.6 percent of water, and from about 3.5 to about 4.5 of a complexone, preferably the tetrasodium salt of EDTA. To ensure the desired properties and consistency of the product as well as successful manufacture, the ingredients have to be mixed in a particular manner and sequence of steps.”
Another example is U.S. Pat. No. 5,700,377 that issued on Dec. 23, 1997, to Cox entitled “Purification of water” that teaches a “chemical composition for use in purifying water used in swimming pools having surfaces that are comprised of materials that do not react with or dissolve in water, comprising for 2.5 kg of the chemical composition, 1.25 kg of potassiumpersulfate, 300 g of sodium bisulfate, 250 g of ammonium chloride, 100 g of aluminum sulfate, 250 g of sodium bicarbonate, 250 g of calcium chloride and 100 g of ethylendiamine tetra acetic acid (abbreviated EDTA). The potassiumpersulfate and the ammonium chloride are effective in disinfecting water to be purified and in eradicating algae and bacteria therein. The sodium bisulfate, sodium bicarbonate and the calcium chloride are effective in balancing the pH of water to be purified to a pH value within an optimum range between 7.2 and 7.6. The aluminum sulfate serves as a flocculation aid and the copper sulfate is effective in the eradication of black algae. The EDTA is effective to complexing heavy metals in the water.”
Additionally, U.S. Pat. No. 4,952,398 issued on Aug. 28, 1990, to Taping entitled “Biocidal composition with copper algicide” that teaches “an improved chemical composition for the treatment of water which is particularly adapted to provide increased biocide activity. By biocide is meant in particular an algacide, a bacetericide and a fungicide. The composition is also suitable for the disinfection of animal breeding places an the cleansing of soil.”
There are typically one or more disadvantages associated with previous attempts to solve the problems of cleaning and sanitizing swimming pools. Previous methods, devices and compositions may not effectively reduce the required level of chlorine, may be associated with staining, may be expensive to produce or may lack the oxidizing effect necessary to kill the full range of bacteria. Additionally, these products may not be intended to assist in removing debris and large particles from water, and may rely on separate filtration systems to do so.
Thus, it is desirable to provide a composition and method effective in minimizing the amount of chlorine necessary to maintain hygienic conditions in contained bodies of water. It is also desirable to provide a composition and method that facilitate and reduce the amount of labor required for the removal of particulate matter and larger impurities from contained bodies of water.
Keeping Contained Bodies of Water Free of Debris
Traditional methods used to contained bodies of water clean include vacuuming the debris and particles that sink to the bottom and skimming the floating debris and particles with a net. There is significant labor associated with the two separate operations of vacuuming the bottom of the contained body of water and skimming the surface with a net.
In response to the problems associated with vacuuming and skimming contained bodies of water, there have been many attempts to develop alternatives to reduce the amount of labor required.
These attempts to solve the problems associated with the labor involved in vacuuming and skimming a contained body of water include the development of special nets and improved vacuuming systems. These devices reduce, but do not totally eliminate, the work associated with the separate operations of vacuuming and skimming contained bodies of water. In general, the combined operations of vacuuming and skimming are more labor intensive than the operation of solely vacuuming particles and debris that sink and accumulate at the bottom of the contained body of water.
Other attempts to solve this problem include devices that continuously circulate water through a filtering system. However, these devices are slow and ineffectual for the large amount of water in most contained bodies of water, and often require vacuuming and skimming in conjunction with their use.
For example, U.S. Pat. No. 6,451,209 that issued on Sep. 17, 2002 to Kaas entitled “A method and system for the treatment of water” teaches “a method and a system for purifying bathing water for a swimming pool (1), water is passed through a filter (2) for filtration of the water. A subflow (6) of the filtered water on the downstream side of the filter is passed through a UV system (3) for photochemical treatment. A second subflow (7) of photochemically treated water is withdrawn from the first subflow (6) for nanofiltration or reverse osmosis treatment in a membrane filter device (4). The invention makes it possible to remove carcinogenic substances, such as THM and AOX from the water. A method according to the invention may also be used for removing biocides, pesticides and peroxides, in order to prepare water for drinking.”
Another attempt for a pool cleaning device using electrical current is covered by U.S. Pat. No. 6,287,450 that issued on Sep. 11, 2001 to Hradril entitled “Apparatus and method for purifying water with an immersed galvanic” teaches a “a water purification system and method suitable for use in swimming pools, spas, hot tubs, water storage tanks, wells and water cooling towers employs a galvanic cell having a silver or copper or zinc anode electrically connected to a cathode made from a metal of still higher electrochemical potential, normally a platinum group metal and preferably palladium. A galvanic cell of some tens of square centimeters in size and some hundreds of grams in weight liberates sufficient silver or copper ions so as to treat a multi-thousand liter body of water, such as a swimming pool, for, typically under normal contamination, some months until the anode is consumed. Copper and/or silver ions liberated from the galvanic cell suppress bacterial, fungal and/or algae growth, thus, significantly reducing the amount of chlorine, bromine or other chemicals needed to maintain water quality. The invention operates on the current generated by the galvanic action between the dissimilar metals of the anode and cathode, and does not require external electrical power.”
U.S. Pat. No. 4,781,805 that issued on Nov. 1, 1998 to Dahlgren entitled “Method for controlling pollution and reducing calcium concentration in aqueous bodies” teaches “a method of an improved method of controlling algal and bacterial pollution, as well as reducing the concentration of dissolved calcium, in a swimming pool, without the necessity of adding electrolytes thereto, involving the steps of: (a) conveying a stream of water from the swimming pool to an enclosed area and back to the pool; (b) providing a pair of spaced-apart electrodes in the enclosed area through which the water is to pass, the electrodes being chemically active and made from mixtures of silver and aluminum alloy containing from about 0.5 to about 5.0 per cent by weight silver and the valance being aluminum alloy; (c) providing a source of alternating electrolytic potential to the electrodes to generate an energy field through the water stream between the electrodes having an rms voltage range from about 25 to about 35 volts and a frequency of alternation of 60 cycles per second to toxify the bacteria and algae in the water and to agglomerate the dissolved calcium into filterable agglomerates; and, (d) providing a filter downstream from the electrodes in the enclosed area for filtering the water as it passes from the electrodes and before it returns to the swimming pool.”
Thus it desirable to provide a composition and method of use to solve some of the problems associated with the use of chlorine to disinfect the water in contained bodies and the keeping contained bodies of water free of particles and debris.